We present a problem dealing with transportation of live animals to slaughterhouses. The problem is taken from the Norwegian meat industry, and may be viewed as a vehicle routing problem extended with constraints to ensure a smooth production flow at the abattoir. In addition, several constraints to ensure animal welfare have to be met. These include… (More)
This master thesis deals with a special variant of the Vehicle Routing Problem (VRP), where there are many customers per road segment. This kind of VRP arises in many real-life situations, e.g. mail delivery and garbage collection. VRP solvers are part of most Decision Support Systems (DSS) used by companies in this business sector. In an operational… (More)
Oil tanker traffic constitutes a vital part of the maritime operations in the High North and is associated with considerable risk to the environment. As a consequence, the Norwegian Coastal Administration (NCA) administers a number of vessel traffic services (VTS) centers along the Norwegian coast, one of which is located in the town of Vardø, in the… (More)
We describe a reasonably simple method for solving the 0-1 Multiconstrained Knapsack Problem (0/1 MKP), and report quite good results. We base our method on tabu search, where moves that contain recently used elements get a penalty. In addition we concentrate on strategic oscillation about the feasibility boundary.
We investigate an optimization problem in container ports, for which previous models based on generalized set partitioning formulations have been studied. We describe two combinatorial relaxations based on computing maximum weighted matchings in suitable graphs. Besides dual bounds, those also provide a variable reduction technique and a matheuristic.… (More)